Heating furnace



J. W. WHITE HEATING FURNACE 2 $hets-Sheet 1 Filed Dec. 1, 1920 1%, "Mai. 1,54%fi2'3 J. W. WHITE HEATING FURNACE kg Fil ed Dec. 1, 1920 7 2Sheets-Sheet 2 m, I? 1 I Q 22, 15 $5 27 3&1

Patented Aug. 18, 1925.

UNITED STATES 1,549,823- PATENT OFFICE.

.IoIm w. WHITE, on DETROIT, MICHIGAN, ASSIGNOR To GENERAL MOTORSCORPORA- TION, OF DETROIT, MICHIGAN, A coRPoRATIoN OF DELAWARE.

HEATING FURNACE.

Application filed December 1, 1920. Serial No. 427,598.

To all wlwm it may concern.

Be it known that I, JOHN W. WHITE, a citizen of the United States, and aresident of Detroit, county of Wayne, and State of Michigan, haveinvented certain new and useful Improvements in Heating Furnaces, ofwhich the following is a full, clear, concise, and exact description,such as will enable others skilled in the art to which the inventionrelates to make and use the same, reference being made therein to theaccompanying drawings, which form a part of this specification.

The invention relates to a furnace adapted for heating articles ingeneral and designed particularly for heating articles which may besuperposed in a stack or pile such as gears or similarly shaped objects,also to a means for conveying articles through a treating chamber, suchas an electric furnace or the like.

The invention has for one of its'objects the provision of a new andimproved furnace, heated by electrical means, and adapted to heatarticles uniformly to the desired temperature with the minimum ofmanipulation and loss of heat.

A further object is to provide a treating chamber such as a heatingfurnace in which the articles to be treated are supported in a stack orpile to which the articles are supplied at one end and from which thetreated articles are removed at the other end.

With the above and other objects in view as will appear more fully fromthe following description the invention consists in the fea tures ofnovelty herein described, together with such variations thereof as fallwithin the scope of the appended claims.

In the accompanying drawings illustrating one embodiment of mvinvention:

Figure 1 is a vertical sectional view of an electric furnace.

Figures 2 and 3 are vertical sectional views respectively of the upperand lower ortions of the furnace shown in Figure 1, but with themovable'parts in different positions, and

Figure 4 is-a plan view of the base of the furnace.

On the drawings 5 indicates a furnace shell within which is a suitablebody of heat insulating material 6. On the interior of the body isarranged electrical heating means 7 which may be of any usual or desiredconstruction and may be supp lied' with heating current from anyconvenient source, as by the conductors 8 leading from a transformer9.

The body of the furnace is retained between end plates 10, 11, theformer of which supports a top plate 12 while the latter rests upon andis secured to a base 29. The top plate 12 is provided with a centralaperture 13 which will be preferably of the same shape in horizontalcross-section as the articles which are to be treated. A depression 14is formed in the top plate at one side of the central aperture whichdepression is adapted to receive below the upper surface of the topplate one of the articles under treatment. withguideways', one of whichis shown at 15, in which slides a cover 16. The cover will be preferablylined with a body of suitable refractory material 17 and may be providedwith a temperature indicating device as 18 adapted to Show thetemperature of the interior of the furnace.

size to the over-all dimensions of one of the articles to be treated.

- A handle 20 attached to one end of a flexible connection 21 passingover a guide pulley 22 and secured at 23 to the cover 16 provides ameans for moving the cover forwardly on the top plate. When the handleis released the cover may be returned to its original position as by theweight 24 and flexible connection 25 passing over pulley 26 and securedto the cover at 27.

It will be understood from the foregoing description that the top ofvthe chamber within the furnace walls will be tightly closed by the cover16 which is designed to fit closely to the surface of the top plate 12.When the furnace chamber has been fully charged, as with a stack of ringgears, the upper one of the stack of articles as the ring gear 28, willlie within the recess 19. If new the cover 16 be moved to the left, asshown in Figure 2, the upper article, as gear 28, will beremoved fromthe stack and deposited in the depression 14 from which it may beremoved automatically or otherwise and pass, as indicated at 28, down anincline or in any other convenient manner to a point of delivery forhardenin or any further treatment to which it is esired to subject thearticles.

The top plate is also provided The base 29 is formed with a centralaperhim 30 in which reciprocates a ram 31, the ram having a reducedportion 32 fitting within the guide 33 and the lower end 34 operating inthe guide 35. The intermediate portion of the ram is slotted asindicated at 36, and in the slot operates a pair of toggle levers 37,38, the lever 37 being pivoted to the ram as at 39 and lever 38 beingpivotally supported upon a bar 40 carried by the lower guide bearing 35and extending through slot 36. A link 41 connected to the toggle leversat their movable joint 42 is attached to an actuating device as lever 43pivoted to the frame as at 44. A stop 38 on lever 38 serves to hold thetoggle looked as shown, and prevents its movement too far beyond thestraight line position.

The structure described constitutes a convenient and powerful means forraising the ram 31 together with the stack of articles which will besupported thereon, but it will be understood that various other forms ofmechanism may be employed within the scope of the invention.

The upper end of ram 31 is covered by a block 45 of refractory and heatinsulating material suitable to support the articles under treatment.Detents 46, the upper ends of which are yieldingly forced inwardly, asby adjustable spring means 47, are pivoted upon the base and arranged toengage over the upper end of the block 45, a wear plate or ring 48 beingprovided to engage with the ends of the detents.

In operation the detents will be so positioned that their upper ends areimmediately below the stack or pile of articles in the heating chamber,their inward movement being limited by the wear ring 48. If now the rambe lowered, as by operation of the toggle mechanism heretoforedescribed, the stack will be supported upon the detents, this permittingthe introduction of another one of the articles to be treated at thebottom of the stack.

The base 29 is hollowed out as at 49 to form a channel having across-section slightly greater than that of the articles to beintroduced into the interior chamber. Any suitable means, automatic orotherwise, may be-provided to supply the articles to this channel. Asshown at 50 they may be fed by gravity along an inclined way.

In the normal operation of the device, the ram having been lowered, asshown in Figure 3, so that the upper surface of block 45 issubstantially at the level of the channel 49, the stack of articles willbe supported upon the detents 46, thus providing a space into which anarticle, as gear 50, may slide to a position immediately below thestack, as shown at 51. By proper manipulation of the ram hoistingmechanism the ram may now be raised to the position indicated. in

Figure 1, thus raising the article 51 up past the detents 46 and intothe lower portlon of the heating or treating chamber. This movement, aswill be obvious, will cause the entire stack of articles to advance adistance equal to the thickness of one article, and will cause theuppermost article to lie within the recess 19 in position to be removedlaterally by proper manipulation of the cover 16, as previouslydescribed.

Thus it will be seen that I have provided a means whereby a stack orpile of articles to be treated may be caused to travel by a step-by-stepprogression through a treating chamber, the articles being added,preferably one at a time, at one end and removed similarly one at a timefrom the other end, without at any time opening the chamber at both endssimultaneously or at either end farther than to the minimum extentnecessary to introduce and remove a single element or fraction of thecharge.

While I have described and prefer the arrangement whereby the charge isintroduced at the bottom and removed from the top, such arrangementbeing of particular advantage in a heating furnace in that it permitsthe progression of the charge from the colder to the hotter portion ofthe furnace, still the invention may also be employed in some of itsdetails in a treating apparatus wherein the direction of travel isreversed or is at any desired angle to the vertical. Various otherchanges may be made in the details of construction and operation withoutdeparting from the spirit and scope of the invention and therefore I donot wish to be limited to the specific structure shown.

It will be understood that, although not limited thereto, the inventionis of especial utility in connection with the heating of articles, suchas gears, preliminary to subjeeting them to the process of hardening. Inoperations of this character it is important that the articles be heateduniformly and accurately to the desired temperature, which temperatureshould be capable of bemg readily regulated at will. These results areeasily attained with the apparatus herein set forth, with the addedadvantages of simplicity of construction, ease of operation, and minimumloss of heat.

I claim 1. In combination, a chamber for treating articles arranged insuperposed relation, means for introducing articles into the chamber atthe lower end thereof to form a stack, and means for removing saidarticles from said stack at the upper end of the chamber, said meansconstructed and arranged to maintain the chamber substantially closed atthe upper end during re moval of articles.

2. In combination, a chamber for treating and means for successivelyremoving articles in predetermined quantities from the upper end of thestack.

3. In combination a "ertically arranged treating chamber, means forintroducing the material to be. treated at the lower end of the chambersaid means comprising a vertically movable ram, and means for removingsuch materialfrom the upper end of the chamber comprising a laterallymovable cover. I

4. In combination a treating chamber, a reciprocatory ram at one end ofthe chamber adapted to force into said chamber an increment of materialto be treated, and a sliding cover for'the other end of the chamber,said cover comprising means for removing from the chamber a portion ofthe treated material. v

5. In combination a chamber, heating means therefor, means forintroducing into said chamber articles to be heated and means forremoving from said chamber ,the heated articles comprising a coverhaving a recess thereinadapted to receive an article, and means'formoving said cover laterally of the chamber.

6. In combination a vertically arranged chamber, heating means therefor,a ram for introducing articles successively into the lower end-of saidchamber, devices for supporting the articles in said chamber during thereciprocations of said ram, and means for removing articles successivelyfrom the upper end of said chamber.

7. A heating furnace comprising a, vertically arranged chamber,electrical heating means therefor, a ram adapted to introduce articlessuccessively into the lower end of said chamber, detents adapted tosupport a stack of articles within said chamber during the reciprocationof said ram, and a sliding cover for the upper end of said chamber, saidcover having a recess adapted to receive a heated article and remove thesame from said chamber by slidingmovement of said cover.

8. In heat-treating apparatus, the combination of a chamber, means forheating said chamber, means for introducing into said chamber materialto be treated, and means for removing successive increments of saidmaterial comprising a sliding cover for said chamber having a recesstherein adapt ed in one position of said cover to receive a portion ofsaid material and in another position to discharge said material outsideof said chamber, said cover adapted to close substantially the dischargeopening in said chamber in both positions.

9. In heat-treating apparatus, the combination of a heating chamber, aram for introducing articles into the chamber at the lower end to form astack, and means for guiding articles to said ram in proper position tobe introduced into the chamber.

10. In heat-treating apparatus, the combination of a heating chamber, aram for introducing articles into the chamber at the lower end to form astack, means enclosing the ram and the lower end of the chamber toobstruct entry of air into the chamber, and a guideway leading to theinterior of said enclosing means for introducing articles to said ram.

11. In heat-treating apparatus, the combination of a heating chamber,means enclosing the lower end of said chamber, a reciprocatory chargingdevice positioned in the lower end of said chamber for supplyingarticles thereto, means through which articles may be introducedsuccessively to said charging device, and-means for supporting articlesin said chamber when thecharging device is in its lowered position.

12. In apparatus for heat-treating articles, a chamber having across-section corresponding approximately to the peripheral contour ofthe articles to be treated, means for introducing articles one at a timeinto the lower end of the chamber to form a stack therein, and means forremoving articles one at a time from the upper end of the chamber.

13. In combination, a heat treating chamber adapted to receive articlesarranged in a stack, means for heating said chamber, means for supplyingarticles successively to the lower end of the chamber to form a stacktherein, and means cooperating with said chamber to prevent circulationof air therethrough during thecharging operation.

In testimony whereof I affix my signature.

JOHN W. WHITE.

